In the Nettalk webinar #7 there was a discussion about how to handle multiple companies using the HostHeader property.
One part of the discussion was the adding of DNS entries to handle different companies.
Example:
C1.mysite.com
C2.mysite.com
You'd need to add CNAME entries C1, C2, etc.
You could get the HostHeader and distinguish between the "companies". The downside is that you need to create A records in the DNS for each company.. or do you?
A better way is to use a DNS Wildcard....
What you can do is add a DNS A entry that says something like:
"*.app" and point it to the correct IP....
So, the User would type "C1.app.mysite.com" and be directed to that IP.
They could type "C2.app.mysite.com" and go to the same IP.
No matter what they type in the URL before ".app.mysite.com", DNS will send them to the correct place.
On your server you would then receive a HostHeader of "C1.app.mysite.com" or whatever they had typed.
1 DNS entry - unlimited "companies"